Abstract: A multi-terminal flexible hybrid DC distribution network constructed with area AC/DC as basic unit has advantages such as convenient access to a variety of power suppy,losd and storage energy device,which has become the development direction of current distribution network.Based on VSC converter of half-bridge sub-module structure,this paper established a multi-terminal DC distribution network model including DC circuit breaker and power electronic transformer,analyzed the system’s operation characteristics from the start,steady-state and fault aspects respectively,which verifies the reliability of system’s control strategy.

Key words: DC distribution network, power electronic transformer, DC circuit breaker, reliability